Surfaces that possess unique wetting behavior, such as superhydrophilicity (surfaces having water contact angles of less than 5°) or amphiphilicity (surfaces having affinity to both hydrophilic and hydrophobic media) are desirable for a number of applications. For instance, surfaces that resist fogging are needed for windshields, safety glasses, and other eyewear. Fog forms when water condenses on a material and beads up to form micron-sized droplets that scatter light, resulting in haziness. Superhydrophilic surfaces often resist fog formation because any condensing water instantly wets the surface to form a transparent thin film rather than individual droplets. However, the anti-fogging properties of these surfaces can be masked by environmental contamination. Thus, surfaces that exhibit easy removal of contamination from grease or dust can help retain anti-fog properties for prolonged exposure times.
The need for easy-to-clean (i.e., easy clean) and anti-fogging surfaces is therefore driving the development of new amphiphilic polymers with reactive groups that can be formulated into robust, durable coatings.